Assessing the Ecological Water Level: The Case of Four Mediterranean Lakes

Olga Petriki,Charalampos Doulgeris,Dimitra Bobori,Dimitrios Zervas

doi:10.3390/w12112977

Abstract

The ecological water regime in lake water bodies refers to the water levels that enable the fulfillment of the ecosystem’s multiple functions. Therefore, assessing the ecological water regime necessitates the consideration of hydrological, economic, social, and ecological factors. The present research is focused on the assessment of the ecological water level of four Mediterranean natural lake ecosystems, considering their morphological and biological features. Initially, suggestions on the ecological water regime of the studied lakes were made based on an analysis of the lakes’ morphometry. Further, the ecological and biological requirements of the present fish fauna and aquatic macrophytic vegetation were considered. For the latter, mapping was conducted by extensive sampling according to international standards, in order to assess macrophyte composition, abundance, and chorology, as well as species sensitivity to water level fluctuations. The above guided the proposals on the optimal water level regime that should be met by each lake regarding the macrophytic and fish communities’ sustainability, also taking into account the unique hydromorphological features of each lake. The differences in the outcoming results revealed that hydromorphological and biological approaches should be combined for assessing lakes’ ecological water regimes.

Highlights

IntroductionLake water levels in the Mediterranean region vary seasonally, due to the clear presence of two hydroperiods i.e., wet (winter) and dry (summer)
Lake water levels in the Mediterranean region vary seasonally, due to the clear presence of two hydroperiods i.e., wet and dry
Based on the above and taking into consideration the water level fluctuations in recent years, the maximum water level for Lake Vegoritida was set at 518 m.a.s.l. (Table 1)

Summary

Introduction

Lake water levels in the Mediterranean region vary seasonally, due to the clear presence of two hydroperiods i.e., wet (winter) and dry (summer). With a lack of anthropogenic disturbance, the highest water level is normally recorded at the end of the wet season (early spring) and the minimum at the end of the dry season (early fall) [2]. This water level pattern may be disturbed due to human activities, which are conducted in the lake catchment, related to urban development and growth of rural areas such as pumping water for irrigation or power generation, flood prevention measurements, diverting streams, and several other hydrological changes [3]. Human interventions can alter the natural intra-annual and inter-annual amplitude of water level fluctuations as well as the seasonal hydroperiod pattern [2,4], resulting in severe impacts on aquatic ecosystems’ functioning and consecutively affecting the biota they support [2].

Methods

Results

Conclusion